Add getter for the obstacles

dune/solvers/iterationsteps/mmgstep.hh

@@ -77,6 +77,9 @@ public:
       obstacles_ = Dune::Solvers::wrap_own_share<ObstacleVectorType>(std::forward<ObstacleVector>(obstacles));
     }
 
+    //! Get the obstacle field
+    ObstacleVectorType& getObstacles() { return *obstacles_; }
+
     //! Set the obstacle restrictor
     template <class Restrictor>
     void setObstacleRestrictor(Restrictor&& restrictor) {